Isolation, characterization and establishment of an equine retinal glial cell line: a prerequisite to investigate the physiological function of Müller cells in the retina.

Retinal Müller glial cells are of vital importance for maintaining a physiological environment within the retina. To this end, they provide highly specialized physiological properties to support neurons in structure, nutrition and metabolism. The purpose of this study was to isolate Müller cells from the equine retina, determine their characteristics and subsequently establish a stable equine Müller cell line (eqMC) that will provide a prerequisite for investigations on their physiological properties. Dissociated retinal cells were obtained from equine retinas by a papain digestion technique followed by trituration and a cell attachment method by which pure Müller cell cultures were achieved. Morphological examination was performed using phase-contrast microscopy, and further characterization of different subcultures was accomplished by immunocytochemistry. Cells of passage 1 showed distinct signals for glutamine synthetase and vimentin, whereas glial fibrillary acidic protein expression was almost absent. Characteristic expression patterns remained unaltered in all subcultures. Furthermore, cultured Müller cells stably expressed the microfilament alpha-smooth muscle actin, the proliferation marker Ki67 and the membrane channels Kir4.1 and aquaporin 4. The present study introduces the eqMC-7 that will facilitate studies investigating the physiological role of Müller cells within the equine retina.

Homeopathy for seasonal allergic rhinitis: rationale, design and methods of the three-armed randomized controlled HOMEOSAR trial.

BACKGROUND: Patients with seasonal allergic rhinitis (SAR) frequently use homeopathic therapy. Although there is some evidence that homeopathy may be effective in treating symptoms of SAR, there is a lack of high-quality clinical trials. Therefore, the aim of the homeopathy for SAR (HOMEOSAR) trial is to determine the efficacy of individualized or standardized homeopathic drug treatment compared to placebo regarding rhinitis-related quality of life in patients with SAR. METHODS: This randomized, placebo-controlled, double-blind, three-armed intervention study will be conducted at two university hospital outpatient clinics for complementary and integrative medicine in Berlin and in 12 office-based practices specializing in homeopathic treatment in Germany. A total of 270 patients with clinical symptoms of SAR and positive allergy test to birch and grass pollen will receive homeopathic anamnesis and subsequently be randomized into (a) standardized homeopathic drug treatment with Galphimia Glauca (potency D6), (b) individualized homeopathic drug treatment (D6), or (c) placebo. All three groups can receive on-demand rescue medication as needed. Treatment will consist of two consultations and daily intake of the study medication for 4 weeks during the pollen season. The primary outcome is the mean overall score of the Rhinitis Quality of Life Questionnaire (RQLQ) in weeks 3 and 4, analyzed using analysis of covariance (adjusted for baseline RQLQ overall score and study center). A closed testing procedure will be used to control the overall type I error comparing the 3 treatment groups. Secondary outcomes include the overall RQLQ and its seven domain scores, responder status (decrease in RQLQ overall score of at least 0.5 points compared to the baseline value), use of rescue medication, intensity of total and individual SAR symptoms based on visual analog scale, generic health-related quality of life, safety, utilization of health care resources and associated costs. In addition, a qualitative data analysis is planned. CONCLUSION: The results of our study will contribute to clarifying the possible therapeutic effects of homeopathic drug treatment for patients with SAR. TRIAL REGISTRATION: This study has been registered in the German Clinical Trial Registry with trial ID DRKS00018081 on June 09, 2020.

Quantification of left atrial contractile function using two-dimensional speckle tracking echocardiography in horses after conversion of atrial fibrillation to sinus rhythm.

INTRODUCTION/OBJECTIVES: In horses, persistent atrial dysfunction is a prognostic indicator of recurrence of atrial fibrillation (AF). The objective of this study was to quantify left atrial (LA) contractile function in Warmblood horses after successful cardioversion of AF to sinus rhythm, using standard two-dimensional echocardiography (2DE) and two-dimensional speckle tracking (2DST) analyses, and to provide proof-of-concept for use of 2DST to detect LA contractile dysfunction in horses. ANIMALS, MATERIALS, AND METHODS: Nineteen Warmblood horses with AF and successful transvenous electrical cardioversion (TVEC) or medical cardioversion using quinidine sulfate (QS) were included. Echocardiography was performed at 24 hr, 72 hr, and 1-6 months after cardioversion. Conventional 2DE-derived indices of LA size and function and global longitudinal strain (SL) and longitudinal strain rate (SRL) during LA contractile function were measured to detect differences in LA size and function over time and between treatment modalities. The association between 2DE-derived indices and global SL and SRL, respectively, and the agreement of the variables to detect LA dysfunction were assessed. RESULTS: Global SL and SRL, as well as active LA fractional area change (FAC) identified cases with LA dysfunction after TVEC and QS cardioversion and proved useful to demonstrate LA functional recovery over time. Agreement between active LA FAC and SL and SRL, respectively, to diagnose atrial dysfunction was substantial to fair at 24 hr after cardioversion and decreased with time. CONCLUSION: This study shows that 2DST is useful to quantify LA contractile dysfunction in horses after cardioversion of AF.

Quantification of left atrial wall motion in healthy horses using two-dimensional speckle tracking.

INTRODUCTION: The mechanical function of the left atrium (LA) plays a pivotal role in modulation of left ventricular filling. Assessment of LA function might be a clinically useful prognostic tool for horses with mitral regurgitation or atrial fibrillation. However, the most accurate, reliable, and clinically useful methods to assess LA myocardial function are yet to be determined. The objective of this study was to describe the methods for quantification of LA wall motion using two-dimensional speckle tracking (2DST) echocardiography in healthy Warmblood horses to quantify measurement variability, to calculate reference intervals for 2DST variables, and to investigate their relationship to sex, age, body weight, and heart rate. ANIMALS, MATERIALS, AND METHODS: Twenty-six healthy Warmblood horses were included. 2DST analyses of LA wall motion were performed on digitally stored cine-loop recordings of a standardized right-parasternal four-chamber view focusing on the LA. Longitudinal strain, longitudinal strain rate, and time to peak LA contraction were measured to characterize LA contractile, reservoir, and conduit function. Intraobserver and interobserver measurement variability was quantified, and reference intervals were calculated. RESULTS: The coefficient of variation for intraobserver and interobserver measurement variability ranged between 2.0-11.1% and 5.1-15.4%, respectively, for global strain, strain rate, and time to peak LA contraction. Reference intervals for healthy Warmblood horses were reported. CONCLUSION: This study shows that 2DST is a feasible and reliable method to quantify LA wall motion throughout the cardiac cycle in healthy Warmblood horses. Further studies are required to establish the clinical value of 2DST for assessment of LA function.

Multi-Stage Group Testing Improves Efficiency of Large-Scale COVID-19 Screening.

BACKGROUND: SARS-CoV-2 test kits are in critical shortage in many countries. This limits large-scale population testing and hinders the effort to identify and isolate infected individuals. OBJECTIVE: Herein, we developed and evaluated multi-stage group testing schemes that test samples in groups of various pool sizes in multiple stages. Through this approach, groups of negative samples can be eliminated with a single test, avoiding the need for individual testing and achieving considerable savings of resources. STUDY DESIGN: We designed and parameterized various multi-stage testing schemes and compared their efficiency at different prevalence rates using computer simulations. RESULTS: We found that three-stage testing schemes with pool sizes of maximum 16 samples can test up to three and seven times as many individuals with the same number of test kits for prevalence rates of around 5% and 1%, respectively. We propose an adaptive approach, where the optimal testing scheme is selected based on the expected prevalence rate. CONCLUSION: These group testing schemes could lead to a major reduction in the number of testing kits required and help improve large-scale population testing in general and in the context of the current COVID-19 pandemic.

Platelet-activating factor acetylhydrolase deficiency. A missense mutation near the active site of an anti-inflammatory phospholipase.

Deficiency of plasma platelet-activating factor (PAF) acetylhydrolase is an autosomal recessive syndrome that has been associated with severe asthma in Japanese children. Acquired deficiency has been described in several human diseases usually associated with severe inflammation. PAF acetylhydrolase catalyzes the degradation of PAF and related phospholipids, which have proinflammatory, allergic, and prothrombotic properties. Thus, a deficiency in the degradation of these lipids should increase the susceptibility to inflammatory and allergic disorders. Miwa et al. reported that PAF acetylhydrolase activity is absent in 4% of the Japanese population, which suggests that it could be a common factor in such disorders, but the molecular basis of the defect is unknown. We show that inherited deficiency of PAF acetylhydrolase is the result of a point mutation in exon 9 and that this mutation completely abolishes enzymatic activity. This mutation is the cause of the lack of enzymatic activity as expression in E. coli of a construct harboring the mutation results in an inactive protein. This mutation as a heterozygous trait is present in 27% in the Japanese population. This finding will allow rapid identification of subjects predisposed to severe asthma and other PAF-mediated disorders.

The bisphosphonate ibandronate improves implant integration in osteopenic ovariectomized rats.

Osteoporosis is known to impair the process of implant osseointegration. Bisphosphonates are drugs that inhibit osteoclast-mediated bone resorption and normalize the high rate of bone turnover that characterizes this disease. Consequently, there is a rationale for using bisphosphonates to enhance the early stabilization of implants in subjects with low bone mass. In this study, 84 rats received titanium-only or hydroxyapatite (HA)-coated titanium femoral implants, 3 months after being ovariectomized (OVX) or sham operated. They were then treated for 4 weeks. The OVX rats were randomly assigned to daily subcutaneous injections of either saline or the bisphosphonate ibandronate (at a dose of 1 microg/kg or 25 microg/kg), while the sham-operated animals received saline throughout. The 1 microg/kg or 25 microg/kg ibandronate doses are considered translatable to doses used to treat osteoporosis and metastatic bone disease (MBD), respectively, in rats, and roughly reflect those used in humans. At the end of the treatment period, bone mineral density (BMD) at the lumbar spine increased in both of the ibandronate-treated groups when compared with the OVX control animals and to a level similar to that of the sham-operated control group. Osseointegration, determined by histomorphometric analysis and expressed as percentage of osseointegration implant surface (OIS), did not differ between groups for the titanium-only implants. For the HA-coated implants, however, OIS was 113.5% and 185% higher in the groups receiving 1 microg/kg or 25 microg/kg ibandronate, respectively, relative to the OVX controls. In turn, the OIS of the HA-coated implants was 56.5% lower in the OVX control group than in the sham control group. These findings clearly demonstrate that OVX-induced osteopenia impairs the osseointegration of HA-coated titanium implants and that ibandronate, administered at doses analogous to those used to clinically treat osteoporosis and MBD, counters this harmful effect. Ibandronate may, therefore, have a role in improving the osseointegration of implants in patients with osteoporosis and MBD.

Fatigue-induced changes to the biaxial mechanical properties of glutaraldehyde-fixed porcine aortic valve leaflets.

Circumferential extension is a direct measure of the preservation of functional collagen crimp in the fibrosal layer of aortic valve leaflets. The aim of this study was to determine whether the elastic properties of zero-pressure, glutaraldehyde-fixed leaflets are changed by mechanical fatigue. Nine Medtronic Freestyle bioprostheses were subjected to 200x10(6) cycles of accelerated fatigue and then biaxially tested to quantify the elastic properties of the leaflets. At physiological load (60 Nm(-1)) the radial extensibility was approximately halved relative to controls (P<10(-4)); there were also lesser reductions in the circumferential extensions (P<.01). The pulsatile regurgitant volume showed no change relative to the control leaflets. The natural corrugations of the fibrosal layer were flattened by the fatigue cycling, but this was not related to an increase in the radial size of the leaflets. Valve competency was maintained.

Hydrodynamic performance of the Medtronic Freestyle Aortic Root Bioprosthesis.

The Freestyle Aortic Root Bioprosthesis is comprised of a porcine aortic root preserved in buffered 0.2% glutaraldehyde solution. It is fixed at a pressure sufficient to distend the aortic wall, but the leaflets are fixed with no transvalvular gradient. The bioprosthesis is treated with alpha-amino-oleic acid (AOA) to reduce the potential for leaflet calcification. In order to conduct in-vitro performance studies, a simulated aorta test chamber was developed. The test chamber material formulation can be altered to produce a wide range of desired compliances, while maintaining repeatable dimensional specifications. The test chamber design also allows for performance testing simulating a variety of implant techniques. Both Freestyle and the stented control valves (Hancock Standard Model 242) were mounted within the simulated aortas for these studies. Steady state and pulsatile flow pressure drop studies demonstrated a significantly lower gradient across the Freestyle valve when compared to stented Hancock Standard controls. In addition, the smaller size (19,21,23 mm) Freestyle valves had superior EOA's compared to the Standard St. Jude bileaflet mechanical and Hancock modified orifice (MO) porcine valve designs. The regurgitant volumes were equivalent to the control (Hancock Standard model 242) valves when compared to the Freestyle valves with equivalent flow areas. Additional studies were conducted in order to determine the effects of sizing and configuration on hydrodynamic performance. These studies were performed in four configurations: total root, inclusion, partially scalloped (two sinuses) and fully scalloped valve. These studies demonstrated that both pressure drop and regurgitation are significantly affected by valve sizing and implant technique. Accelerated wear studies were performed on three of each size and six of the largest Freestyle valves. Stented Hancock Standard valves and non-AOA treated Freestyle valves were used as controls. Hydrodynamic performance tests were conducted at intervals throughout the study. No evidence was found to indicate a difference in wear or hydrodynamic performance between the AOA treated and untreated Freestyle valves.

Mitral E wave propagation as an index of left ventricular diastolic function. I: Its hydrodynamic basis.

BACKGROUND AND AIMS OF THE STUDY: Left ventricular (LV) diastolic dysfunction is an early sign of myocardial disease and an important determinant of symptoms and prognosis in patients with various cardiovascular disorders. Evidence suggests the presence and clinical importance of abnormal LV diastolic function in patients with valvular heart diseases, but it is difficult to measure non-invasively. Mitral E wave propagation inside the left ventricle studied by analysis of digitized color M-mode and pulsed wave Doppler technique is a promising technique for the evaluation of LV relaxation. However, the precise mechanism of its transmission is not clearly defined. Understanding the precise hydrodynamic basis of E wave propagation would be helpful for its meaningful application to the evaluation of LV diastolic performance. This study investigates the hydrodynamic determinants of mitral E wave propagation in an in vitro setting. METHODS AND RESULTS: Thirty-one sets of experiments were conducted in a linear, pulsatile left ventricle model with varying operative diastolic characteristics. The rate of transmission of the onset of the E wave was strongly related to operative LV diastolic stiffness (r = 0.93, p < 0.0001), and weakly to mean left atrial (LA) pressure (r = 0.46, p < 0.01), heart rate (r = 0.57, p < 0.01) and stroke volume (r = -0.58, p < 0.01) through an effect on operative LV diastolic stiffness. The peak of the E wave transmission was influenced not only by operative LV diastolic stiffness (r = 0.87, p < 0.0001), but also by the mean LA pressure, heart rate and stroke volume, in an independent fashion. CONCLUSIONS: The rate of transmission of the onset of the mitral E wave is determined solely by operative LV diastolic stiffness, whereas that of the peak is also affected by the mean LA pressure, heart rate and stroke volume. Analysis of mitral E wave propagation in patients with valvular heart disease may give clinically useful insights into LV diastolic function.

cDNA cloning, expression and chromosomal localization of two human lysophosphatidic acid acyltransferases.

In this report we describe a pair of human LPAAT isozymes. These isozymes are encoded by distinct genes located on different chromosomes, but share sequence homology, substrate specificity, and intracellular location. The biological value of maintaining the two closely related LPAAT genes in the human genome is not clear. We find that both isozymes are widely expressed, although expression levels do diverge significantly in tissues such as the liver, placenta, testes, and pancreas. We also find that, at least in the artificial system of over-expression in COS7 cells, both isozymes localize to the ER membrane. Thus, distinct tissue-specific or subcellular compartment-specific roles for the two isozymes are not supported by the current experimental evidence. It does remain possible that induction of expression or subcellular translocation of one or the other isozyme may distinguish their functions. A survey of a limited number of acyl CoA substrates indicates that the two isozymes display similar substrate specificities, although slight differences are suggested by the data. However, extensive analysis of both isozymes with multiple substrates in the same assay system will be required to detect physiologically relevant differences in substrate specificity. LPA and PA are central intermediates in phospholipid biogenesis. Furthermore, they have the capacity to mediate signaling both between and within cells. The importance of these mediators is reflected in the growing body of literature dedicated to unraveling the mechanistic basis for their actions. Until recently, the field has been hampered by a dearth of reagents appropriate for the molecular dissection of the LPA and PA metabolic and signaling pathways in eukaryotes. However, the recent cloning of possible LPA receptors will promote further understanding of LPA signaling. Similarly, the recent appearance of LPAAT homologs in the EST database has prompted a flurry of reports describing their characterization. These clones will afford opportunity for defining the function of LPAAT in eukaryotic phospholipid metabolism.

Plasma heparin values and hemostasis in equids after subcutaneous administration of low-dose calcium heparin.

Different doses of heparin were given to equids SC to establish 0.05 to 0.20 U of heparin/ml of plasma. Plasma heparin values and antithrombin III activities were assayed, using chromogenic substrate methods. Activated partial thromboplastin and thrombin times were determined, using conventional coagulation assays. Tests were run every hour (or every 2 hours for antithrombin III) for 12 hours from 5 groups of 5 equids each after single injection of 40, 60, 80, 100, or 125 U of calcium heparin/kg of body weight and from 11 equids after injection of 150 U of calcium heparin/kg. The smaller dose (40 U/kg) did not or only insufficiently increase plasma heparin values. After 150 U of heparin/kg, plasma heparin concentrations were increased for 11 hours and were significantly (P = 0.05) increased between postadministration hours 2 and 7. The desired range beyond 0.05 U of heparin/ml was achieved between postadministration hours 2 and 6. Antithrombin III, activated partial thromboplastin time, and thrombin time were not significantly affected by any heparin dose. In cumulative studies, 2 equids were given 150 U of heparin/kg 7 times at 12-hour intervals. After the 3rd injection, a mean plasma concentration of 0.20 U of heparin/ml was achieved; after the 7th injection, the mean concentration was 0.22 U of heparin/ml. Four equids were given 150 U of heparin/kg initially, followed by 125 U of heparin/kg 6 times at 12-hour intervals. After the 3rd injection, a maximal plasma heparin concentration of 0.12 U of heparin/ml was achieved; after the 7th injection, the mean concentration was 0.18 U of heparin/ml. Repeated SC heparin injections caused moderate swelling at the injection sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in sexual attitudes and likeliness of sexual behaviors of black lower-socioeconomic father-present vs. father-absent female adolescents.

This study compared sexual permissiveness attitudes and likely behaviors of father-absent vs. father-present black, lower-socioeconomic female adolescents. Father-absent subjects were not found to be more sexually permissive in reported likely behavior or attitude than father-present subjects. However, the father-absent group was found to have significantly greater inconsistency between behavioral and attitudinal scores in which the reported behavior was more permissive than the reported attitude. Finally, within the father-absent group, those subjects whose fathers became absent before they were five years old, were found to have a significantly higher need for social approval than subjects whose fathers became absent after they were five years old. The implications of these results are discussed.

Early detection of skin cancer (EDISCIM) through the use of non-invasive confocal imaging.

In the past 15 years the number of malignant melanomas and non-melanoma skin cancer, (i.e. squamous cell carcinoma, basal cell carcinoma), have increased dramatically throughout the whole world, in particular among people with white skin. For example, in Germany the number of new cases of melanoma is about 10 to 12 per 100,000 people, (for basal cell carcinoma as a non-melanoma skin cancer 140 per 100,000), the absolute number of annual new cases of melanoma is an estimated 9,000 to 10,000, and the increasing rate is 5 to 10%. However, there are more than 40 differential diagnoses for skin cancer which makes it difficult even for expert dermatologists to give correct diagnosis, (estimated 75% correct diagnoses). This figure is even worse for doctors from other specialities. There is only a chance of high cure rates when skin tumours are detected at an early stage. The prognosis of skin cancer is dependent very much on the thickness, (as a sign of invasiveness), of the tumour and the number of mitotic figures in the tumour, (as a sign of proliferation activity). However, the final diagnosis of skin cancer is usually done by biopsy, the sample being investigated by a specialist. This is an invasive method, which is painful for the patient and might require several cuts and samples taken before being absolutely certain. Due to the potential risk of dissemination of tumour cells, taking an incisional biopsy is obsolete in malignant melanoma. Therefore the correct diagnosis of malignant melanoma can be made only after a total removal of the lesion and consecutive histopathological examination. The EDISCIM project intends to develop a system for the early diagnosis of skin cancer which uses confocal imaging for the non-invasive diagnosis of the upper layers of the skin that aids the physician in the analysis of the images and therefore with the diagnosis, allows for potential remote diagnosis by specialist dermatologists via tele-diagnosis if need be. The objectives of the system are Captures microscopic images of the skin by confocal imaging, Processes and records these images in real time, Compares these images against a knowledge base of known skin symptoms, Displays the results in a suitable interface to the physician performing the diagnosis, And supports the online telematic support by specialists.

[Comparison of IgG determination in foals using commercially available rapid tests]. / Vergleich der IgG-Bestimmung beim Fohlen mit Hilfe im Handel erhältlicher Schnelltests.

The three tests (EQUI Z-Test, AGLUTINADE FOAL IMMUNITY, CITE Foal IgG-Test) were evaluated for their accuracy and usefulness in the field. Single radial immunodiffusion was used as reference method. All tests were easily and rapid to perform and results were obtained within a few minutes. It was easy to get the results of the CITE Foal IgG-Test, but use of the EQUI Z-Test and the FOAL AGLUTINADE IMMUNITY-Test needed some practice to get correct results. Results obtained by the CITE Foal IgG-Test correlated to single radial immunodiffusion in 94%, those obtained by FOAL AGLUTINADE IMMUNITY-Test in 74.1% and those obtained by EQUI Z-Test in 57.1%. Best results with a correspondence of 97.1% (CITE Foal IgG-Test) and 100% (EQUI Z-Test) were seen in the group having > 800 mg IgG/100 ml and in the group having < 200 mg IgG/100 ml with 93.3% (CITE Foal IgG-Test) and 82.1% (EQUI Z-Test). The AGLUTINADE FOAL IMMUNITY-Test had the same accuracy in all groups (70.9%-77.8%).

Evaluation of the role of heterogeneities on transverse mixing in bench-scale tank experiments by numerical modeling.

In this work, numerical modeling is used to evaluate and interpret a series of detailed and well-controlled two-dimensional bench-scale conservative tracer tank experiments performed to investigate transverse mixing in porous media. The porous medium used consists of a fine matrix and a more permeable lens vertically aligned with the tracer source and the flow direction. A sensitivity analysis shows that the tracer distribution after passing the lens is only slightly sensitive to variations in transverse dispersivity, but strongly sensitive to the contrast of hydraulic conductivities. A unique parameter set could be calibrated to closely fit the experimental observations. On the basis of calibrated and validated model, synthetic experiments with different contrasts in hydraulic conductivity and more complex setups were performed and the efficiency of mixing evaluated. Flux-related dilution indices derived from these simulations show that the contrasts in hydraulic conductivity between matrix and high-permeable lenses as well as the spatial configuration of tracer plumes and lenses dominate mixing, rather than the actual pore scale dispersivities. These results indicate that local material distributions, the magnitude of permeability contrasts, and their spatial and scale relation to solute plumes are more important for macro-scale transverse dispersion than the micro-scale dispersivities of individual materials. Local material characterization by thorough site investigation hence is of utmost importance for the evaluation of mixing-influenced or -governed problems in groundwater, such as tracer test evaluation or an assessment of contaminant natural attenuation.

Evaluation of transverse dispersion effects in tank experiments by numerical modeling: parameter estimation, sensitivity analysis and revision of experimental design.

Transverse dispersion represents an important mixing process for transport of contaminants in groundwater and constitutes an essential prerequisite for geochemical and biodegradation reactions. Within this context, this work describes the detailed numerical simulation of highly controlled laboratory experiments using uranine, bromide and oxygen depleted water as conservative tracers for the quantification of transverse mixing in porous media. Synthetic numerical experiments reproducing an existing laboratory experimental set-up of quasi two-dimensional flow through tank were performed to assess the applicability of an analytical solution of the 2D advection-dispersion equation for the estimation of transverse dispersivity as fitting parameter. The fitted dispersivities were compared to the "true" values introduced in the numerical simulations and the associated error could be precisely estimated. A sensitivity analysis was performed on the experimental set-up in order to evaluate the sensitivities of the measurements taken at the tank experiment on the individual hydraulic and transport parameters. From the results, an improved experimental set-up as well as a numerical evaluation procedure could be developed, which allow for a precise and reliable determination of dispersivities. The improved tank set-up was used for new laboratory experiments, performed at advective velocities of 4.9 m d(-1) and 10.5 m d(-1). Numerical evaluation of these experiments yielded a unique and reliable parameter set, which closely fits the measured tracer concentration data. For the porous medium with a grain size of 0.25-0.30 mm, the fitted longitudinal and transverse dispersivities were 3.49×10(-4) m and 1.48×10(-5) m, respectively. The procedures developed in this paper for the synthetic and rigorous design and evaluation of the experiments can be generalized and transferred to comparable applications.